Method and Apparatus for Patient-Controlled Medical Therapeutics

ABSTRACT

An apparatus and associated methods are provided to authenticate a patient based on a biometric identifier of the patient before a prescribed dose of medical therapeutic, such as analgesics or other medication, are dispensed to the patient. Authentication takes places by pressing a button and scanning the patient&#39;s fingerprint and recording data corresponding to the fingerprint into memory. To receive the medical therapeutic, the patient can have his or her fingerprint read and compared to the stored fingerprint. If there is a match and the programmed limitations are met (e.g., a time interval has elapsed since the last dose), then the medical therapeutic is automatically dispensed to the patient. The system may be integrated with a new patient-controlled medical therapeutic device or the system may be added to an already existing device. Other features and advantages of the example embodiments are described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/396,847 filed Apr. 3, 2006, the contents of which are incorporated byreference herein in its entirety

FIELD OF INVENTION

The present invention relates to methods and apparatuses for use inmedical therapeutics, and more specifically, relates to methods andapparatuses in which the patient can control the dispensing of medicaltherapeutics, such as pain medication, anesthesia or other medication ortherapies.

BACKGROUND

Pain management remains an area of heightened concern for the healthcare industry. The most prevalent and traditional method of painmanagement is nurse-administered analgesia. Analgesic describes amedication that alleviates pain. Nurse-administered analgesia typicallyresults in larger and less frequent doses of pain medication than moremodern methods. This form of dosing can lead not only to lessefficacious pain control but also significant complications likeover-sedation, respiratory depression and death.

More recently, patient-controlled analgesia (“PCA”) andpatient-controlled epidural analgesia (“PCEA”) have become the preferredmethods of administering analgesic as they allow the patient to uniquelycontrol his or her own pain. These devices and similarly operativedevices, in which a patient manages his or her pain, are collectivelyreferred to herein as “PCA” devices. In comparison with thenurse-administered analgesic method, the PCA is designed to allowdelivery of a smaller amount of analgesic in a more frequent dosingpattern. Typically, a PCA device is set up next to the patient and isprogrammed by a nurse or authorized caregiver to deliver certainanalgesics to the patient upon the patient's command or request. Toreceive the command, there is typically a cable or wire attached to thedevice with a button on the end that extends to the patient. The patientcan press the button to give a prescribed amount of intravenous orepidural analgesic to him or herself.

It is thought by some in the health care industry that patients candevelop a synergism with the PCA device and can effectively manage theirpain with less medication thus decreasing side effects like pruritis,dysphoria, hypotension, hypoventilation, bradycardia, andnausea/vomiting. In addition, the PCA device prevents overmedication,and therefore, significantly reduces the risk of cardiopulmonarycompromise (e.g., respiratory depression) and death. In the advancementof pain management, then, many PCA type devices have been released onthe market and have become a popular form of pain management. Earlymodels usually consisted of a syringe pump connected to a timingmechanism used as a safeguard to prevent an overdose. At the push of thebutton by the patient, pain medication is administered in small bolusdoses assuming a minimum amount of time between each dose has expired.More modern PCA devices include microprocessors to digitally managelockout intervals and dosage amounts, yet such devices still operatewith a simple push button command.

Even with the advancement of modern PCA devices, some patients are stillreceiving too much analgesic, therefore leading to life-threateningcomplications. While it is typically believed that a sedated patientwill not press the button to deliver more medication, family members,caregivers, and sometimes clinicians are administering the analgesic forthe patient by “proxy,” (also referred to herein as “PCA by proxy”)hoping to keep the patient comfortable. This well-intentioned effort hasbeen reported to lead to major complications, up to and including death.Indeed, the Joint Commission on Accreditation of Healthcare Organization(“JCAHO”) has recognized the importance and danger of PCA by proxy andissued a sentinel event alert concerning the issue on Dec. 20, 2004.

One current approach to addressing PCA by proxy is to educate thehealthcare industry, patients, families, and visitors to the hazards ofimproper PCA use. Another approach is provided in U.S. Pat. No.6,899,695, entitled “Medication Security Apparatus and Method,” given toHerrera, which uses a voice sound recognition algorithm to create avoice print that distinguishes the patient's voice command from othervoices to ensure that only the patient controls the bolus dose tohimself or herself.

There continues to be a need for improved pain management. Unlike thetraditional nurse-administered methods of pain management, with PCAdevices, the patient provides a measure of safety him or herself becausean over-sedated patient will not be capable of pushing the PCA button.Thus, the previous doses can “wear off” by the processes ofredistribution and elimination effectively moving the patient towardssafety rather than overdose and complication. PCA by proxy has beenidentified as a significant breakdown of this effective and otherwisesafe device. A need still exists to significantly reduce or eliminatethe risk of PCA by proxy in a way that provides a seamless transitionfrom current methods and can be used effectively in a hospital or otherpatient care setting.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the example embodiments may be better understood withreference to the following drawings. The components in the drawings arenot necessarily to scale, emphasis instead being placed uponillustrating example embodiments.

FIG. 1 illustrates a front-view of an example patient-controlled devicefor use in administering medication to a patient upon command from thatverified patient;

FIG. 2 illustrates a cutaway side-view of an example fingerprint sensorfor use with the patient-controlled device shown in FIG. 1, the examplefingerprint sensor is used for patient fingerprint sampling andauthentication;

FIG. 3 illustrates a block diagram of the various components that may beused by the example patient-controlled device shown in FIG. 1 toauthenticate the patient and release the medication;

FIG. 4 shows a flow chart for illustrating an example process ofrecording a patient's fingerprint for use in later authenticating thepatient; and

FIG. 5 shows a flow chart for illustrating an example process forauthenticating a patient for delivery of medication by comparing ascanned fingerprint to a previously stored fingerprint.

DETAILED DESCRIPTION I. Overview

An apparatus and associated methods are provided for use in patientcontrolled medical therapeutics and the use of biometric technology toauthenticate patients. The preferred embodiments are directed towardsapparatus and associated methods for use in patient controlled painmanagement and the delivery of analgesic, but the invention is notlimited to pain management and could be applied to any medicaltherapeutic generally, including anesthesia, other medications andtherapies. The preferred embodiments are also directed towards the useof fingerprint biometrics to authenticate patients, but the invention isnot so limited and could be applied to any biometric technology that issuitable for use in a hospital environment.

The apparatus of the preferred embodiments includes the use of apushbutton and a fingerprint sensor to authenticate the patient before aprescribed dose of medication is administered to the patient. Inresponse to an activation, the fingerprint sensor captures an image ofthe patient's finger and relays the information to a processor, whichdetermines whether a match exists with a previously stored fingerprint.Activation of the fingerprint sensor is preferably caused by thedepression of a pushbutton. If the patient depresses the pushbuttonoutside of a lockout period (if any such lockout period or time limit isprogrammed) and the fingerprint match is successful, the processor willsend a signal to a release mechanism/delivery device (a pump in apreferred embodiment) corresponding to the PCA device to subsequentlyrelease medication (e.g., analgesic) from a vial or container to thepatient. While the use of a pushbutton is not required, exampleembodiments described herein include the use of a button or pushbuttonto indicate the patient's intention of requesting more pain medication;“pushbutton,” as used herein, refers to any type of actuation device andincludes any type of pressure sensitive surface, switch, or button. Anysuch actuation device may be substituted herein for “pushbutton.” Withrespect to other biometric technologies, such as retinal scanners, otheractuation devices as known in the art could be used.

In an alternative example embodiment, upon a successful fingerprintdepression of the pushbutton and match, the PCA device may initiate someother form of pain management that does not necessarily include liquidmedication. Examples of other forms of pain management includeiontophoresis, which involves ion movement through biological tissueunder the influence of an electric current, and transdermal, in which adrug is introduced into the body through the skin.

The example embodiments overcome drawbacks typically found in modern PCAtype devices by authenticating the patient using fingerprint biometrictechnology before analgesic is released. This authentication processwill reduce or eliminate the risk of “PCA by proxy” and its attendantcomplications. The use of a fingerprint scan effectively prevents theunauthorized use of the PCA device because it requires authentication ofthe patient in a way that cannot be easily copied or recorded like otherauthentication means.

The example embodiments are also effective and suitable for use in ahospital or other patient care facility, in which the preferredatmosphere is one of a quiet and peaceful nature. By using fingerprintbiometric technology, the amount of added “noise pollution” to theenvironment is kept to a minimum. This remains true even if the patientrequests hundreds of doses of analgesic in a twenty-four hour period.This feature is especially important when patients share rooms or whenfamily or friends are gathered in the patient's room.

According to one example embodiment, the security device is packaged ina manner that makes a near seamless transitional device change from theconventional pushbutton method. Integrating fingerprint biometrictechnology with that of a pushbutton makes for a smooth and relativelyeasy transition from a non-secure method of pain management to one thatis secure.

According to another example embodiment, the security device includes anencasement or housing to prevent unauthorized dispensing of analgesic.In this embodiment, the encasement makes it increasingly difficult touse the patient's finger (or a false finger) to dispense analgesicwithout the patient's need or consent.

The example embodiments can be utilized with existing PCA devices orcompletely integrated with new PCA devices. To use with existing PCAdevices, for example, the fingerprint authorization process can beintegrated with the traditional pushbutton mechanism. The traditionalpushbutton may be left attached and the fingerprint authorizationmechanism may be added to the system, such that a command to dispenseanalgesic comes only after the pushbutton is depressed and authorizationoccurs. Alternatively, the traditional pushbutton may be removed andreplaced by an integrated pushbutton and fingerprint sensor. Of course,the example embodiments may also be completely integrated into thedesign of new PCA devices. It will be understood that the system can beprogrammed such that the example steps described herein (e.g.,depressing the pushbutton and scanning the fingerprint) can occur in anyorder or at the same time. Also, it will be understood that “depressingthe pushbutton,” as used herein, can include the steps of depressing thepushbutton and releasing, or can include only depressing the pushbutton(not requiring the step of releasing).

Additionally, while the fingerprint authorization mechanism may be usedto authenticate the patient when administering doses, the authenticationmechanism can also be used to authenticate other users of the PCAdevice, such as physicians and caregivers, before giving them access toprogram the PCA device or provide an extra, but necessary dose to thepatient. This feature may be especially useful for pediatric patientswhen parents (or other persons) are authorized to use the PCA device onbehalf of the child. Alternatively, a separate fingerprint sensor may beused to authenticate other users of the PCA device.

Other features and advantages of the apparatus and associated methodswill become apparent to one with ordinary skill in the art uponexamination of the following drawings and description. Additionally, theteachings described herein, such as a security device for a PCA deviceusing a fingerprint authenticating mechanism, may be applied to othertypes of medical devices that are used to dispense medication or otherforms of therapy to a patient. As such, the present invention is not tobe limited to the example embodiments described herein, andparticularly, the present invention is not to be limited to use with anyparticular type of patient-controlled analgesia device.

II. Example Pain Management Apparatus and Associated Methods

FIG. 1 illustrates an example PCA-type apparatus 100 with a fingerprintsensor/pushbutton 114 for use in administering controlled doses ofmedication (e.g., analgesic) to an authenticated patient. The exampleapparatus 100 generally includes, but is not limited to, a video display104, function keys 102 for programming the apparatus 100, a container(such as a drug vial) 106 for storing medication or analgesic, adelivery device or release mechanism (e.g., a pump) 108 for releasingmedication or analgesic, tubing 110 for delivering the medication to thepatient intravenously or through some other method of delivery,actuation device 112 which includes a fingerprint sensor/pushbutton 114and corresponding conductive wire 116 for providing the authenticationsignal (the request for medication) to the delivery device/releasemechanism of the apparatus 100.

The present invention is not limited to any particular type of containerfor storing medication or to any particular type of deliverydevice/release mechanism. For example, the present invention can utilizeiontophoresis combined with a transdermal patch in which medication isdelivered through a transdermal patch and in which the delivery iscontrolled electronically.

According to the example embodiments, the apparatus 100 is generallyplaced next to the patient's bed and the actuation device 112 may beheld remotely by the patient or clipped to the bed near the patient. Theapparatus 100 may also be carried by a handle or wheeled if the devicehas been fastened to a wheeled pole. Power may be provided to theapparatus 100 by a wall outlet or through some other power source likebatteries (not shown in the figure). Power converters (also not shown inthe figure) may be used to adjust the voltage to levels required tooperate the control module, release mechanism/delivery device, and/orother electronics corresponding to the apparatus 100.

To program the apparatus 100, it may be desirable to first require apassword or some other means of authentication. For instance, thephysician or authorized caregiver may enter their password to gainaccess to the control unit of the apparatus 100. Alternatively, thecontrol unit of the apparatus 100 may be programmed to read thephysician or authorized caregiver's fingerprint through fingerprintsensor/pushbutton 114. In another alternative embodiment, the physicianor caregiver may have their fingerprint scanned by another machine forauthentication (e.g., not fingerprint sensor/pushbutton 114), in whichcase, the control unit of the apparatus 100 is in direct or indirectcommunication with the other machine to receive the fingerprint or anauthorization signal. Just like the patient, to be described below, thephysician or caregiver can have their fingerprint initially scanned byany designated fingerprint sensor (which can be the same as or differentfrom fingerprint sensor/pushbutton 114) and stored at the apparatus 100,or alternatively, in a database reachable by an accessible network.Regardless of how the fingerprint is scanned, if the fingerprint of thephysician or caregiver matches a pre-recorded fingerprint stored intomemory of the control unit or stored remotely in a database accessibleover a network, then access may be granted.

A physician or authorized caregiver may program the apparatus 100through function keys 102 and video display 104 to deliver—whencommanded by the patient—certain sized doses of medication to thepatient at limited intervals. These time limits are also referred toherein as “lockout periods,” such that the medication will not beadministered at any time during or within a lockout period. Theselockout periods can be programmed for any reason, but are particularlyuseful to prevent the patient from receiving too much medication. Theapparatus 100 may also be programmed to continuously dispense medicationto the patient as indicated. Moreover, the type of medication containedin the container 106 may also be programmed into the control unit of theapparatus 100 through keys 102 and display 104. In another embodimentand generally found in more sophisticated and modern PCA devices, thecontainer 106 may contain a bar code that, if provided, a bar codereader on apparatus 100 can read the vial's bar code to automaticallyprogram some pertinent information, thereby reducing the chance foroperator error. Other types of systems may exist or will be developed inthe future that can be used to prevent this type of operator error.Dosing quantities and lockout periods, such as specific time intervallimitations, may also be programmed into the control unit automaticallyvia a bar code on the container 106 or through some other mechanism.

When in operation, the patient can control, preferably within theprogrammed limits, the amount of medication that is dispensed by placinga finger (whichever fingerprint(s) was previously stored into memory ofthe control unit or stored remotely in a database accessible over anetwork) over the pushbutton and fingerprint sensor 114 of the actuationdevice 112 for authentication. According to one example embodiment, torequest a dosage of medication the patient depresses a button in theactuation device. The pushbutton may be integrated with the fingerprintsensor 114, such that upon depression of the pushbutton, the fingerprintsensor 114 will scan the fingerprint. It is understood that while thepushbutton and the fingerprint sensor 114 may be integrated, thepreferred function of the fingerprint sensor 114 is to determine whetherthe patient is authenticated and the preferred function of the button isto determine the patient's intentions (e.g., determining whether thepatient is simply resting his/her finger on the actuation device orwhether the patient is requesting more pain medication). As previouslystated above, other types of actuation devices may be used in place ofthe pushbutton. Also, if a pushbutton is used, it does not have to beintegrated with the fingerprint sensor. It should also be understoodthat while the example embodiment calls for scanning the fingerprintupon depression of the button, the present system is not to be limited;for example, the fingerprint sensor may periodically and continuouslyscan the finger resting on the button such that upon depression of thebutton, the patient has already been verified.

Once the patient is authenticated and the button is depressed, and ifthe requested dose is within the programmed limits, the deliverydevice/release mechanism 108 (in one preferred embodiment, a pump) willautomatically dispense a controlled amount of medication from thecontainer 106 to the patient through tubing 110. If liquid medication isnot used, then instead of dispensing analgesic in liquid form to thepatient, another form of pain management or treatment can be initiatedupon authentication and button depression (e.g., iontophoresis, etc.) Ifthe patient cannot be verified through the fingerprint sensor/pushbutton114 or an unauthorized person has attempted to deliver a dose ofmedicine, then in addition to not providing a dose of medicine, thecontrol unit may provide an alert, which can be an audible or visualalert, electronic message or any other type of alert. The alert mayremain local to the apparatus 100, and if so desired, an alert signalmay be automatically transmitted to a nurse's station or desk to notifya caregiver that the patient cannot be authenticated or of an error thatrequires attention.

The history of all button presses, fingerprint scans, and alerts, amongother things, may be stored either at the apparatus 100 or in a databaseon a network. This data may be useful to determine information like thenumber of button presses, when the button presses occurred, whoattempted to press the button, the type of dosage given, the amount ofmedicine given and so on. This information can be useful for securityreasons as well as for treatment of the patient.

According to one example embodiment, the actuation device 112, whichincludes the fingerprint sensor 114, is not covered or encased. Rather,the fingerprint sensor 114 and button are exposed so that a patient caneasily and effectively command a dose of analgesic. In this embodiment,the actuation device 112 provides a seamless transition from currentmethods (e.g., the use of a button to dispense medication), yet thepresent system provides an effective means to authenticate the patientbefore dispensing pain medication. This example embodiment may be usefulfor any application, but particularly useful for users with rheumatoidarthritis (who require simple maneuvering), those with languagebarriers, variable IQ levels, and so on by providing a straightforwardpain management solution.

It is envisioned that in some instances, however, a person other thanthe patient may attempt to override the authentication process byplacing the patient's finger on the pushbutton/fingerprint sensor andpressing the button, thereby dispensing an extra and perhaps unneededdose of analgesic to the patient. This may happen during times when thepatient is sleeping, unconscious, or without consent of the patient. Inview of this, the actuation device 112 may include a covered or encasedsensor to prevent someone from wrongfully using the patient's finger (ora false finger) thereby providing an unauthorized dose of medication tothe patient.

An example of this alternative embodiment is shown in FIG. 2. Morespecifically, FIG. 2 illustrates an example of an encased actuationdevice 200, which was previously shown in FIG. 1 as 112, for use inauthenticating a patient. Actuation device 200 includes a housing orencasement 210 for encasing fingerprint sensor/pushbutton 202,authentication electronics 204, and stop 208. The housing or encasement210 may be connected to the fingerprint sensor/pushbutton 202 in anymanner. This housing 210 may be made of rigid plastic or an equivalentmaterial. According to this example, the patient inserts a finger intothe opening of the fingerprint sensor 200 and upon depression of thebutton (or simply applying pressure to the button or surface); thefingerprint sensor/button 202 captures an image of the finger. Thepushbutton is used in combination with the fingerprint sensor 202 toinitiate the authentication process. Preferably, the encasement designis such that flexion at the distal interphalangeal joint (“DIP”) wouldbe necessary, more of which is described below.

Irrespective of whether the pushbutton and fingerprint sensor areencased or not, the process of scanning and authentication preferablyremains the same. Fingerprint scanning is generally the acquisition andrecognition of a person's fingerprint characteristics for verificationpurposes. This allows the recognition of the patient throughquantifiable characteristics that verify the patient's identity. Anytypes of finger-scanning technology may be utilized. Example methodsinclude an optical method, which starts with a visual image of a finger,and another method that uses a semiconductor-generated electric field toimage a finger. It is to be understood that the present system is notlimited by the finger-scanning technology utilized.

Fingerprint sensor/pushbutton 202 then communicates data correspondingto the image or some form thereof to the authentication electronics 204.Authentication electronics 204 generally includes memory and a digitalsignal processor for executing stored program instructions thatdetermines whether a match has occurred with a fingerprint stored intomemory and the image. Authentication electronics could embody actualcircuitry or be software that works in conjunction with a processor.Examples of fingerprint matching techniques may include minutiae-basedand/or correlation based techniques. If a match is found, a signal fromthe authentication electronics 204 travels to the releasemechanism/delivery device and/or control unit of the apparatus throughwire 206 to dispense the medication. The authentication electronics 204may be positioned as shown near the fingerprint sensor/button oranywhere, such as at the PCA device itself or remotely and accessiblevia a network or some other means.

In an effort to reduce or eliminate the possibility of overriding theauthentication process, a stop 208 may be utilized so that the patienthas to bend his or her finger inside the actuation device 200 toactivate the authentication process. Of course, the actuation device 200may be designed differently to produce the same or similar results, suchas an angled surface, which would require articulation at the DIP joint.For example, the actuation device 200 could be designed such that thepatient has to insert his or her entire finger or a substantial portionof the finger into the device—thereby making it increasingly difficultfor someone other than the patient to activate the authenticationprocess.

If an encased design is utilized, it is preferable to have a “one-sizefits all” device for ease and convenience. However, it is alsoenvisioned that various sizes may be used to accommodate differingfinger sizes. Additionally, it is preferred that the encasement can beremoved for easy cleaning. As an additional safeguard, the actuationdevice 200 may include a sensor that sends a signal to the PCA devicewhen the encasement is removed and the fingerprint sensor/pushbutton areexposed. This signal could cause the PCA device to decline fromproviding a dose of medication if requested. Alternatively, or inaddition to a removable encasement, a thin film may be inserted over thepatient's finger or placed directly into the encasement and over thefingerprint sensor/pushbutton for each user. For sanitary purposes, thethin film can be thrown out and replaced for each user. Alternatively,the actuation device 200 or any part thereof may be disposable such thatit could be allocated to a single user or a limited number of users.

It is to be understood that the present invention is not limited to theactual design and/or layout shown in FIG. 1 or FIG. 2. It will beappreciated by those of ordinary skill in the art that other designsand/or layouts may be utilized to provide a security mechanism forauthenticating a patient by his or her fingerprint before a dose of painmedication is administered. For example, in an alternative embodiment tothe actuation device 200 shown in FIG. 2, some or all of theauthentication electronics 204 may be moved to a location at theapparatus 100 or to some other location accessible through a network. Insuch an alternative, the data from the captured image at the fingerprintsensor 202 may be communicated over a wire (or wirelessly) to theauthentication electronics at the apparatus where it is determinedwhether a match exists. The flexibility of the design and/or layout isfurther described with respect to FIG. 3.

FIG. 3 illustrates a block diagram 300 of various components that may beused to administer medication to an authenticated patient. Included inthe diagram 300 are fingerprint sensor/pushbutton 302, processor 304,memory 306, release mechanism/delivery device (e.g., a pump) 308, andalert mechanism 310. Each of the components may communicate with eachother through a wired or wireless connection, and therefore, the actualplacement of the components may be of little significance (e.g., FIG. 2provides an example placement).

An example of a commercially available fingerprint sensor is BLP-100,which is a pressure sensitive fingerprint sensor manufactured by BMFCorporation, in Japan. In a preferred embodiment, a pushbutton isintegrated with the fingerprint sensor. Once the pushbutton isdepressed, the fingerprint sensor can scan the patient's fingerprint.

An example processor is BCT-100, which is a controller for the BLP-100and also manufactured by BMF Corp. Alternative examples include theFingerprint Biometric System from Texas Instruments. Some aspects of theauthentication process may be embodied in the form of a computer programproduct that is stored on a computer readable storage medium and isexecuted by a suitable instruction system. Any suitable computerreadable medium may be utilized including hard disks, CD-ROMS, opticalstorage devices, magnetic storage devices, or any type of known computerreadable medium.

Memory 306 includes permanent and/or temporary memory such as read onlymemory (“ROM”), random access memory (“RAM”) or any variation of RAM,such as static RAM or static-dynamic RAM. The memory 306 may be on boardthe PCA device or additionally on a network that is readily accessibleby the PCA device. According to a network accessible embodiment, thediagram 300 may show the various components communicating with a networksuch that the fingerprint samples may be stored and/or downloaded from adatabase accessible over the network. A central depository of authorizedfingerprint(s) may then be kept at the hospital or facility. Also, if sodesired, limitations and/or rules can be programmed into the database toallow only certain users to be authorized for particular PCA device(s)(e.g., a particular nurse may be authorized for PCA device #2, #3, and#4, but not for #5 or #1). This embodiment will preferably limit thenumber of times a physician or caregiver will have to input theirfingerprints.

In a preferred embodiment, release mechanism/delivery device 308 is aninfusion-type pump that infuses fluids, medication or nutrients into apatient's circulatory system upon verification of the patient. Forexample, it may be used intravenously, although subcutaneous, epidural,intrathecal infusions, or others systems/methods may also be used.

The alert mechanism 310 may include a speaker for making certainprogrammed noises when such alert is needed. The alert mechanism 310 maybe triggered during the fingerprint scanning process, when the dose isadministered, or when the user cannot be authenticated. The alertmechanism 310 may exist on the PCA device itself or at some otherlocation on a network. The alert mechanism 310 may also include loggingthe alerts in a database, either on the PCA device itself or in adatabase on the network. Further, the speaker may be used to provideauditory cues while using the device. For example, differential soundsmay be used to indicate an accepted versus rejected fingerprint scan andauthentication.

FIG. 4 shows a flow chart illustrating an example process of recording apatient's fingerprint for use in authentication. Various blocks in FIG.4 may represent a module, segment, or portion of code, which includesone or more executable instructions for implementing specific logicalfunctions or steps in the process. Alternate implementations areincluded within the scope of the preferred embodiments in whichfunctions may be executed out of order from that shown or discussed,including substantially concurrently or in reverse order, depending onthe functionality involved, as would be understood by those reasonablyskilled in the art. Further, it is understood that some steps may notneed to be actually implemented to achieve the desired result ofscanning the patient's fingerprint into memory.

At block 400, the apparatus 100 is turned “on” and is ready to acceptinput commands from the operator (e.g., a physician, caregiver, or someother authorized user). Power is also supplied to the fingerprintsensor/pushbutton 114. According to one example embodiment, thefingerprint sample is taken at the PCA device. According to analternative, the fingerprint sample is taken on another machine using adifferent fingerprint sensor and is stored in a database that isaccessible by the PCA device over a network or accessible by some othermechanism.

At block 402, the authentication module is set to record a fingerprintsample. In this state, the module is ready to receive a new fingerprint.Previous fingerprint samples may be discarded or the new fingerprint maybe added to the system. Preferably, an alert is provided to indicatethat the module is ready for the patient to insert his or her finger.

At block 404, the patient inserts his or her finger into the actuationdevice and presses the finger against the pushbutton. In addition toencased designs, as previously mentioned, to prevent false fingers frombeing used the system may also incorporate a device to measure bloodflow or check for correctly arrayed ridges at the edges of the fingers.

At block 406, the fingerprint sensor scans the patient's fingerprint andrecords its characteristics. Various characteristics of the fingerprint,such as whorls, arches, and loops may be recorded along with thepatterns of ridges, furrows, and minutiae—the type of information andthe amount of information recorded may depend on the scanning technologyor algorithm used. This information may then be processed or stored intomemory as an image or as an encoded computer algorithm to be comparedwith other fingerprint samples. According to another embodiment, thefingerprint samples can be stored anywhere, such as in memory on thenetwork. An alert may be provided to indicate the fingerprint scan wassuccessful. If the scan was not successful, then a different alert mayindicate to try the process again. Further, additional fingerprint scanscan take place (e.g., to record a caregiver's fingerprint for his or herauthentication, and so on).

At block 408, the process of recording a fingerprint sample ends.

FIG. 5 shows a flow chart for illustrating an example process forauthenticating a patient for delivery of medication by comparing ascanned fingerprint to a recorded one. Various blocks in FIG. 5 mayrepresent a module, segment, or portion of code, which includes one ormore executable instructions for implementing specific logical functionsor steps in the process. Alternate implementations are included withinthe scope of the preferred embodiments in which functions may beexecuted out of order from that shown or discussed, includingsubstantially concurrently or in reverse order, depending on thefunctionality involved, as would be understood by those reasonableskilled in the art. Further, it is understood that some steps may notneed to be actually implemented to achieve the desired result.

At block 500, the control module and the authentication module arepowered and ready to receive a command from the patient.

At block 502, the patient places his or her finger over the pushbuttonand fingerprint sensor. As described earlier, in one example embodiment,the pushbutton and fingerprint sensor are not encased, so the patientcan simply place the finger over the pushbutton. Also described earlier,in another example embodiment, the pushbutton and fingerprint sensor areencased, so the patient will insert his or her finger into the housingand place it on the pushbutton.

At block 504, the patient or authorized caregiver depresses thepushbutton and the fingerprint sensor scans at least a portion of thepatient's fingerprint. As described earlier, the system is not limitedto any particular order of operation. For instance, the system may beprogrammed to receive a signal from the pushbutton first, and then thefingerprint sensor will scan the fingerprint. In another instance, thesystem may be programmed to periodically scan the fingerprint and thenthe patient can depress the pushbutton at any time. In yet anotherinstance, the pushbutton and fingerprint sensor may perform theirfunction at the same time. Regardless of operation, the systempreferably recognizes that the patient is requesting another dose ofmedicine (e.g., through the activation of the pushbutton) and the systemis attempting to authorize the patient (e.g., through the scanning ofthe fingerprint).

At block 506, the software then searches for similar information in thedatabase (in memory at the PCA device or on a network). Often analgorithm is used to encode the information into a character string thatcan be searched for in the database, improving search time. The databasemay not actually have an image of the fingerprint, but a set of datarepresenting the fingerprint that can be used for comparison. If thefingerprint does not match, the patient is denied and the process can goback to block 502. If the fingerprint does match (authentication), thenthe process goes to block 508.

At block 508, it is determined whether the pushbutton was depressedoutside of a programmed time limit or lockout period. If the pushbuttonwas depressed within such a programmed time limit or lockout period, thepatient is denied and the process can go back to block 502, If thepushbutton was depressed outside of the programmed time limit or lockoutperiod, the process goes to block 510 for delivery of medication.

At block 510, a prescribed dose of medication is dispensed by therelease mechanism/delivery device to the patient. The process can againbe repeated at block 500.

At block 512, the example process for authenticating a patient fordelivery of medication ends.

As previously mentioned, the history of all button presses and/orfingerprint scans may be stored—either at the PCA device or on thenetwork. It may be useful to know who was pressing the button and whenthe button was pressed and/or if the patient was authenticated. It mayalso be useful to record information related to the authentication suchas medication type, dosage, frequency, programmed amounts, and so on. Apaper report or an electronic report, or both can be generated with thistype of information.

III. Conclusion

The example embodiments described herein provide for an improved devicefor dispensing medication (in a preferred embodiment, analgesic) to apatient using a fingerprint analyzer. The example embodiments aredescribed in relation to a patient-controlled analgesia device thatdelivers a prescribed amount of intravenous or epidural analgesic to thepatient when he or she activates the release mechanism/delivery deviceand upon fingerprint verification. Of course, the teachings describedherein may be applied to other patient controlled medication dispensingdevices or patient controlled therapy. The teachings described hereinmay also be applied to other types of biometric technology that would besuitable for use in a hospital environment.

An advantage of the apparatus and associated methods includes theprevention of someone other than the patient from activating the releasemechanism/delivery device. This eliminates or reduces the risk ofadministering the analgesia for the patient “by proxy.” Thus, thepresent system eliminates or reduces this potentially dangerous aspectof modern PCA devices.

Another advantage is that the fingerprint authentication mechanism maybe used with existing PCA type devices to prevent unauthorized use ofthe device. It provides a seamless transition from current methods toone that provides an effective means by which the patient or user isauthorized.

Another advantage of the apparatus and associated methods is that it canbe operated in the peaceful and quiet surroundings normally associatedwith a hospital or patient care facility, e.g., nursing home or someother environment where a patient would require use of a PCA device.

Another advantage is that the fingerprint samples may be stored at thePCA device or in a database accessible over a network. According to thenetwork embodiment, a central database may be utilized to storefingerprints for use in authenticating the user. In this way, aphysician or caregiver can be authorized for any PCA device withincommunication of the network. Also, if so desired, limitations and/orrules can be programmed into the database to allow only certain users tobe authorized for particular PCA device(s).

The example embodiments of the present invention have been describedherein. It is to be understood, of course, that changes andmodifications may be made in the example embodiments without departingfrom the true scope of the present invention. Aspects of the exampleembodiments may include logic to implement the described methods insoftware modules as a set of computer executable software instructions.A processor implements the logic that controls the operation of theauthentication mechanism. The processor executes software that can beprogrammed by those of skill in the art to provide the describedfunctionality.

The software can be represented as a sequence of binary bits maintainedon a computer readable medium described above, for example, as memorydevice 306 in FIG. 3. The computer readable medium may include magneticdisks, optical disks, and any other volatile or (e.g., Random Accessmemory (“RAM”)) non-volatile firmware (e.g., Read Only Memory (“ROM”))storage system readable by the processor. The memory locations wheredata bits are maintained also include physical locations that haveparticular electrical, magnetic, optical, or organic propertiescorresponding to the stored data bits. The software instructions areexecuted as data bits by the processor with a memory system causing atransformation of the electrical signal representation, and themaintenance of data bits at memory locations in the memory system tothereby reconfigure or otherwise alter the unit's operation. Theexecutable software code may implement, for example, the methods asdescribed above.

It should be understood that the programs, processes, methods andapparatus described herein are not related or limited to any particulartype of vial or container, pumps, processors, memory or storage devices,display units, input capabilities, and so on, unless indicatedotherwise. Various types of general purpose or specialized processorsmay be used with or perform operations in accordance with the teachingsdescribed herein.

It should further be understood that a hardware embodiment might take avariety of different forms. The hardware may be implemented as anintegrated circuit with custom gate arrays or an application specificintegrated circuit (“ASIC”). The embodiment may also be implemented withdiscrete hardware components and circuitry. In particular, it isunderstood that the logic structures and method steps described in theflow diagrams may be implemented in dedicated hardware such as an ASIC,or as program instructions carried out by a microprocessor or othercomputing device.

The claims should not be read as limited to the described order ofelements unless stated to that effect. In addition, use of the term“means” in any claim is intended to invoke 35 U.S.C. §112, paragraph 6,and any claim without the word “means” is not so intended. Therefore,all embodiments that come within the scope and spirit of the followingclaims and equivalents thereto are claimed as the invention.

1. A patient-controlled system for dispensing medication to a patient at times determined by the patient in an in-patient setting, comprising: a fingerprint sensor for reading at least a portion of a fingerprint of the patient's finger when the finger is positioned on the fingerprint sensor; a patient activated actuation device operatively associated with the fingerprint sensor; an encasement connected to the fingerprint sensor and the patient activated actuation device for impeding the ability for a person other than the patient to use the patient's finger to activate the patient activated actuation device; a microprocessor for receiving data from the fingerprint sensor, the data representing the portion of the fingerprint, and analyzing the data by comparing the fingerprint to a previously stored fingerprint to verify the patient; and a delivery device connected directly to the patient for administering a prescribed amount of the medication to the patient based on the activation of the patient activated actuation device by the patient and verification of the patient. 